Question: If $a + b = 9$ and $x + y = 1$, what is $-3b - 3y - 3a - 3x$ ?
Explanation: $= -3a - 3b - 3x - 3y$ $= (-3) \cdot (a + b) + (-3) \cdot (x + y)$ $= (-3) \cdot (9) + (-3) \cdot (1)$ $= -27 - 3$ $= -30$